## **Core Concept**
Tooth sensitivity, particularly in the context of a Class V lesion and bruxism, requires a restorative material that can withstand occlusal forces and provide a good seal against microleakage. Bruxism involves grinding and clenching of teeth, which can lead to increased wear and tear on dental restorations.

## **Why the Correct Answer is Right**
The correct answer, **C. Bulk-fill composite**, is suitable for this patient due to its properties that make it ideal for restorations subject to occlusal forces, such as those seen in bruxism. Bulk-fill composites can be placed in thicker increments (up to 4 mm) without significant shrinkage stress, reducing the risk of debonding and improving marginal integrity. This characteristic makes them particularly useful for Class V restorations where achieving a durable seal can be challenging.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Microfill composites have high polishability and are often used for anterior teeth or for surface layering to improve aesthetics. However, they may not offer the same level of durability under occlusal forces as bulk-fill composites.
- **Option B:** Flowable composites are easy to adapt to the cavity walls and can be used for lining or as a base under other composites. However, they have higher shrinkage rates and lower wear resistance compared to bulk-fill composites, making them less suitable for a restoration subject to bruxism.
- **Option D:** Conventional composites require incremental layering to minimize shrinkage stress and may not be as efficient in handling the thickness required for bulk-fill restorations.

## **Clinical Pearl / High-Yield Fact**
A key consideration in managing tooth sensitivity and restorations in patients with bruxism is selecting materials that can withstand increased occlusal forces. Bulk-fill composites not only offer a practical solution due to their ease of placement but also provide improved mechanical properties compared to traditional composites.

## **Correct Answer:** C. Bulk-fill composite.